Tachometer.



I No. 733,358.

PA-TENTED JULY 7, 1903.

U. H. VEEDER.

TAOHOMETER.

APPLIGATION'IILED FEB. 1a, 1903.

4 SHEETS-SHEET 1v N0 MODEL.

8140041 601 6441a. 72 004. Qfl'oumuq f 2 o, PHOTO-LIT PATENTED JULY 7,1903.

C. H. VEEDER.

TAGHOMETER.

APPLIUATION FILED FEB. 18, 1903.

4 SHEETS-SHEET 2.

NO MODEL.

a l l 51400 for M 1410 M Slfotl/utytK/ PATENTED JULY 7, 1903.

U. H. VEBDER.

TACHOMETER.

APPLICATION IILED FEB. 18, 1903.

4 SHBETS-SHEET 3.

N0 MODEL.

f l z/ do M memes PATENTED JULY 7, 1908. 'G. H. VEEDER. TA GHOMETER.

APPLICATION FILED FEB. 18, 1903.

4 SHEETS-SHEET 4.

N0 MODEL.

ERS co. PHO GLIYnQ, f/ASNINGTUN, n.

1 qml Ii'g. 8.

ratnted July v, loos.

PATENT OFFI E.

CURTIS HUSSEY VEEDER, on HARTFORD, CONNECTICUT.

TACHOMETER.

SPECIFICATION forming part of Letters Patent No. 733,358, dated July 7,190a; Application filed February 18, 1903. Serial No. 143,935. (Nomodel.)

F0 aZZ whmn it may concern:

Be it known that I,CURTIs HUssuvVEEDnR, a citizen of the United States,residing in Hartford, county of Hartford, in the State of Connecticut,have invented certain new and useful Improvements in Tachometers, ofwhich the following is a specification, reference being had to theaccompanying drawings, forming a part hereof.

This invention relates to apparatuses or instruments for measuring thespeed of shafts, wheels, the, and machines of various classes. In anapplication for Letters Patent of the United States filed by me on May6, 1902, and serially numbered 106,130, thereis illustrated anddescribed a tachometer for measuring more particularly the speed ofmotor-vehicles and in which the difference in the level of twocommunicating columns of liquid placed side by side indicates the speedat whichthe machine to which said tachometer is attached is beingdriven. When said tachometer is in a vertical position, the level of theliquid in the indicator-tube (one of the columns of liquid) and thelevel of the liquid in a reservoir (the other of the columns of liquid)will mark the zero of the speed-indicating scale; but if for any reasonthe tachometer is tilted, as will often be the case with a portabletachometer, the liquid in the indicator-tube will either be depressed orraised above its normal position, according to the degree and directionof the tilting and according to the distance between the indicator-tubeand reservoir, as will be clearly seen upon reference to theaforesaidapplication. Slightvariationsfrom true readings will also occurwhen the velocity of the instrument changes suddenly either in rate ordirection, as will often happen to instruments mounted on automobiles.Such variations are due to the inertia of the liquid and are especiallynoticeable when the changes of velocity occur in the plane of the twocolumns of liquid. \Vhile the tachometer described in said applicationgives accurate results in most cases where the instrument is verticallydisposed and results sufficiently accurate for most purposes,notwithstanding thcinertia of the liquid, and though the instrument beslightly tilted from a vertical position, such as would occur when it ismounted on a motor-vehicle, still for certain purposes the instrumentshould be made to read with the greatest possible accuracy under allconditions.

Accordingly one object of the present invention is to provide atachometer of the class described which shall be so constructed that theerrors in the reading of the instrument due to tilting and inertia maybeminimized.

A further object of the invention is to provide for such disposition ofthe outlet or discharge pipe of the pump, which communicates with theindicator-tube, that the pump may be run in either direction with thesame effect upon the liquid in the instrumentthat is, with a likedisplacement of the liquid in either case for the same speed ofrotation. In order to carry out this object of the invention, saidoutlet-pipe is radially disposed with respect to the pump-propeller.

A still further object of the invention is to provide means foradjusting the level of the liquid in the indicator-tube with referenceto the graduated scale, whereby when the instrument is first filled foruse or whenfrom time to time the liquid is replenished the column ofliquid in the indicator-tube may be quickly and accurately set tocorrespond with the scale.

In the drawings, wherein is illustrated an instrument which embodies thepresent invention, Figure 1 is a view in front elevation of saidinstrument. Fig. 2 is a detail view, partly in elevation and partly insection, on the plane indicated by the line 2 2 of Fig. 3, thepump-casing being partly broken away to show the interior constructionof the pump. Fig. 3 is a view. in central vertical section taken on theplane indicated by the broken line 3 3 in Fig. 1. Fig. at is a top View.Fig. 5 is a detail view taken on the plane indicated by the broken line5 5 in Fig. 3. Fig. 6 is a View, partly in section and partly iiielevation, showing the indicating mechanism located at a distance fromthe pump, communication being established between the indicatingmechanism and the pump by suitable pipes. Figs. 7, 8, and 9 are detailedviews, partly in section, illustrating different positions of a valvewhich may be used in connection with the device.

As stated above, the form of tachometer shown and described in saidapplication has a liquid reservoir and an indicator tube placed side byside. In order to provide against any inaccuracies of measurement,which, as heretofore shown, might arise when that form of tachometer istilted from a vertical position, the indicatortube according to thepresent invention is disposed concentrically with respect to thereservoir instead of at one side thereof, as in the old form. In thedrawings the indicator-tube a is shown as mounted upon the base bat thecenter of the reservoir 0, which is also formed upon base I). The sidesof the reservoir are parallel and symmetrical with the axis or centerline of the indicator-tube, and they are preferably of glass in orderthat the condition of the liquid in the reservoir may be convenientlyobserved from time to time, sight-holes being provided in the metallicexterior casing c for this purpose.

a bracket (1, which is tapped to form a passage d, communicating withboth tubes in order that the pressure upon the surface of the liquid inboth the indicator-tube and the reservoir may be equal. A guard-rod dextends from the top of the reservoir to the bracket cl to protect theindicator-tube, which is preferably formed of glass throughout. Apacking-ring a and thumb-nuts a are provided to secure theindicator-tube readily in position and to permit it to be easily andquickly removed and a new tube inserted whenever desirable.

As was the casein the old form of tachometer, which has been referredto, the indieating devices just described maybe mounted directly uponthe pump-casing, Figs. 1 and 3, which in such case serves as a supportfor said indicating devices, or the pump and the indicating devices maybe separated, Fig. 6, the pump being placed near the moving partthespeed of which is to be measured and the indicating devices located in aplace where they may be conveniently observed. Different conditions ofuse will determine in which manner it will be the more convenient tounite the pump and indicating devices. For portable instruments it willas a rule be preferable to mount the indicating devices directly uponthe pump in some such manner as is illustrated in Figs. 1 and 3 of thedrawings, while for use onautomobiles, for example, it will generally bethe more convenient to separate the pump and indicating devices in orderto place the pump near one of the vehicle-wheels and the indicatingdevice on or near the dashboard in front of the driver. In the formshown in Figs. 1 and 3 a portion of the pump-casing e is formed integralwith the base I) of the indicating devices, said base and easing beingtapped to form passages connecting the suction of the pump'with thereservoir and the discharge of the pump with the indicator-tube.

It will A filling-tube 0 which may: be regarded as a continuation of thereservoir be obvious, however, that aside from the mere question ofconvenience there will be some cases where the pump will be required tobe separated from the indicating devicesas, for instance, where the pumpis required to be set up in a particular position, conceivably at aconsiderable inclination, in order to be properly connected to themoving or actuating part. Inasmuch as the indica tor-tube should alwaysbe as nearly as possible in a vertical position, for reasons abovestated, it will be necessary in such cases that the pump and indicatingdevices be separable, as will readily be seen. As illustrated in Fig. 6,the pump and indicating devices are thus removed from each other andcommunicate through suitable pipes and l. It should be observed herethat when theinstrumentis set up for use the liquid-conduits connectingthe pump to the reservoir and indicator-tubethat is, the pipes orpassages 70, 70, Z, and Zshould head upwardly at all points and besubstantially uniform throughout to prevent the formation of pocketswhere bubbles might collect in the liquid.

Any form of pump may be used in said tachometer which is capable ofdisplacing the liquid therein to cause a change of level of the liquidof the reservoir without, however, actually causing a positive transferof the liquid from the reservoir to the indicatortube. The pump employedin the present case to bring about this result comprises a suitableshell or casing 8, before referred to, having suitable hearings for ashaft f, upon which blades or paddles g are mounted to rotate freelywithin the casing e. In said casing there is a draw-off cock u, throughwhich a quantity of liquid may be removed in order to bring the level ofthe liquid to the zero of the scale when filling the instrument andthrough which the instrument may be completely emptied when it isdesired. The shaft of the pump maybe connected mechanically in anysuitable way with the moving or actuating part, the means shown in Figs.3 and 4 of the drawings comprising a pulley 7L, keyed upon said shaftand adapted to receive a belt or chain driven by said part, while themeans shown in Fig. 6 comprise a sprocket-wheel h on the shaft,connected by a chain 77.2 with the moving or actuating part.

In the casting constituting the base I) and a portion of the pump-casinge a chamber 1, Fig. 2, is formed, which communicates with the reservoir0 through a channelj and with the suction of the pump through a channel7c, communication being thus established between said reservoir and thesuction of the pump. Said casting is also tapped to form a passage Z toconnect the periphery or dis charge of the pump with the indicator-tubea, and said passage, Fig. 5, is radially disposed with respect to thepumppropeller, so that when the pump is'rotated at equal speeds ineither direction the same displacement of the liquid in the instrumentwill take place.

It will therefore be obvious that the instrument will always be adaptedto measure speed correctly without regard as to whether the pump isbeing run backward or forward. It is also desirable that the outlet Z beplaced centrally with respect to the pump-chamber in order to reduce toa minimum the effect of eddies within the pump-chamber. A valve Zcontrolled by a handle Z is provided in said passage for regulating themovement of the liquid, and thereby to render the instrument moresensitive and to especially prevent the dancing of the liquid in theindicater-tube when the instrument is jarred.

The valve Z for regulating the resistance between the pump and theindicator-tube and a valve for controlling the connections between thereservoir, the pump, and the indicator-tube for filling, testing, oroperating, combined in onestructure, are represented in Figs. 7 to 9. Asingle valve-plug U has a seat in the base of the instrument and isprovided with a channel U to establish communication between the pipeZand a passage N into the reservoir, a hole U at right angles with thechannel U to establish communication between the pipe Z and theindicatortube, and at its end with an ear U to close the passage M fromthe reservoir to the pipe 7t. During the filling of the instrument thevalve-plug Uis in the position shown in Fig. 7, in which the passage Mis closed, and communication between the reservoir and theindicator-tube is established through the channel U, thus allowing theliquid,which is introduced at the top of the reservoir extension, toenter the indicator-tube also, by which the quantity of liquidintroduced is indicated. When the valve-plug is turned to either of thepositions shown in Figs. 8 and 9, the liquid descends into the pipes andpump until they are properly filled. The valve-plug being then in theposition shown in Fig. 8 the pump is started and the liquid iscirculated from the reservoir, through the pump, and back to thereservoir to separate all air-bubbles from the liquid, the reservoirbeing at this time connected with the pipe through the passage M, whichis open, and with the pipe Z through the passage N and channel U.Finally during the operation of the instrument the valve-plug is in theposition shown in Fig. 9, in which the passage M is open, the passage Nis closed, and communication between the pipe Z and the indicatortube isestablished through the hole U By turning the valve-plug slightly fromthe position shown in Fig. 9, so as to place the hole U slightly out ofexact alinement with the pipe Z and indicator-tube, the resistance tothe movement of liquid from the pump toward the indicator-tube may bevaried. If at any time it is desired to test the instrument, even whenthe pump is in operation, the valve-plug is turned to the position shownin Fig. 7, thus cutting off both reservoir and indicating-tube from thepump.

Seated in the casting b and adapted to be moved into and out of chamber2' therein is displacement-plunger m, Fig. 2, by which the area orcapacity of said chamber 71 may be varied, thereby raising or loweringthe level of the liquid in the indicator-tube, as may be necessary inadjusting the instrument. Suitable packing a and a packing-ring 0 areprovided around said plunger, being held in place by a nut p, threadedto the wall of the plunger-cavity. A thumb-screw q, held fromlongitudinal movement by engagement with the nutp, is threaded to theplunger, whereby the position of the latter with respect to thechambert' may be adjusted to a nicety.

A scale '1' is secured to the instrument near the indicator-tube and ismarked with proper preferred, the graduations may be marked upon theindicator-tube itself.

The lower part of the instrument may be formed with aconveniently-shaped base .9, provided with clamping-screws 'Zforsecuring it in position when used as a stationaryinstrument, as upon avehicle or other machine.

The operation of the improved tachometer will be understood from theforegoing description. In filling the instrument asuitable liquid, suchas colored alcohol, is introduced through the filling-tube c, asuflicient quantity of s uch liquid being supplied to bring the level ofthe same just above the zero-point of the scale. The level of the liquidis then roughly adjusted to the zero of the scale by means of a draw-offcock, and finally screw (1 is turned to move the plunger to the preciseposition in chamber 11 to set the level of the liquid in theindicatortube exactly at zero. when these adjustmentshave beencompleted, the instrumentis ready for use. As the vehicle or driven partis speeded up the column of liquid in the indicator-tube will be causedto change its level with reference to the liquid in the reservoir, so,that if the scale is made to read up, as shown in Fig. 1, the column ofliquid in the indicator-tube will rise, the amount of rise varyingapproximately with the square of the speed of the revolution of thepump. Of course the pump does not act positively to transfer the liquidfrom the reservoir to the indicator-tube; but the blades of the pumpwill slip more or less in the liquid, so that when the change in levelof the two columns for the given speed has been attained no furthermovement of the liquid in theindicatortube will take place, and the topof the column will remain at substantially the same height until achange in speed occurs. It will be evident that in an instrumentconstructed in accordance with the foregoing the errors in the readingsdue to tilting will be substantially eliminated, both for the reasonthat the pump and indicating mechanism are separable and because theconcentrically-disposed indicator-tube will minimize any slightdiscrepancies from the true readings which might occur under unusualconditions. It will also be evident that the reversibility of the pumpwill obviate the necessity of changing the position of the instrument,as would otherwise be required when the speed of the moving partrevolving backward is to be determined.

Various changes in the construction and arrangement of parts can be madeto suit the conditions of use; but such changes will obviously fallwithin the scope of this invention, which is not limited to the preciseconstruction shown and described.

I claim as my invention- 1. A speed-indicator comprising aliquidreservoir, an indicator-tube concentrically disposed with respectto said reservoir, and a pump interposed between the reservoir and theindicator tube, substantially as described.

2. A speed-indicator comprising a liquidreservoir, an indicator-tubeconcentrically disposed with respect to said reservoir, and acentrifugal pump, the reservoir being connected with the suction of thepump and the indicator-tube being connected with the discharge of thepump, substantially as described.

3. A speed-indicator comprising a liquidreservoir, an indicator-tubeconcentrically disposed with respect to said reservoir, a pumpinterposed between the reservoir and the indicator-tube and anadjusting-valve interposed between the pump and the indica-- tor-tube,substantially as described.

4. A speed-indicator comprising a liquidreservoir, an indicator-tubeconcentrically disposed with respect to saidreservoir, a pump interposedbetween the reservoir and the indicator-tube, one of said parts beingconnected to the suction and the other to the discharge of the pump, andan adjustingvalve interposed between the pump and the indicator-tube,substantially as described.

5. A speed-indicator, comprising a liquidreservoir, an indicator-tube, abase upon which said reservoir and tube are mounted and having therein achamber, a pump, the reservoir and chamber communicating with theindicator-tube through the pump and a plunger adapted to be moved in andout of said chamber, substantially as described.

6. A speed-indicator comprising a liquid reservoir, an indicator-tube, abase upon which said reservoir and tube are mounted and having therein achamber, a pump, the reservoir and chamber communicating with theindicator-tube through the pump and a plunger adapted to be moved in andout of said chamber, a nut engaging said base, and a thumb-screw heldfrom longitudinal movement by engagement with the nut and having athreaded engagement with the plunger, 7

substantially as described.

7. A speed-indicator comprising a liquidreservoir, an indicator tube, abase upon which said reservoir and tube are mounted and having therein achamber, a pump, the reservoir and chamber communicating with theindicator-tube through the pump and a plunger adapted to be moved in andout of said chamber, packing surrounding said plunger, a packing-ringalso surrounding said plunger, and a threaded nut engaging said base andcooperating with said packing-ring, substantially as described.

8. A speeddndicator comprising a liquidreservoir, an indicator-tube, abase supporting said reservoir and tube, said base having acharnbercommunicating with the reservoir, a valve located in said base toregulate the movement of the liquid into said tube, a pump interposedbetween but separated from said reservoir and tube, and pipes connectingsaid reservoir and tube with the pump, whereby the pump may be tiltedwithout atfecting the indicating mechanism, substantially as described.

9. A speed-indicator comprising a liquidreservoir, an indicator-tube, abase supporting said reservoir and tube, said base having a chambercommunicating with the reservoir, a plunger adapted to be moved in andout of said chamber, a pump interposed between but separated from saidreservoir and tube, and pipes leading upward at all points connectingsaid reservoir and tube with the pump, whereby the pump may be tiltedwithout afiecting the indicating mechanism, substantially as described.

10. A speed-indicator, comprising a liquidreservoir, an indicator-tube,a base supporting said reservoir and tube, said base having a chambercommunicating with the reservoir, a valve located in said base toregulate the movement of the liquid into said tube, a pump separatedfrom said reservoir and tube, a pipe connecting said reservoir with thesuction of the pump, a pipe connecting said indicator-tube with thedischarge of the pump whereby the pump may be tilted without affectingthe indicating mechanism and a drawoff cock in the pump-casing,substantially as described.

11. A speed-indicator comprising a liquid reservoir, an indicator-tubeconcentrically disposed with reference to the reservoir, a basesupporting said reservoir and tube, a pump interposed between butseparated from said reservoir and tube, pipes connecting said reservoirand tube with the pump, whereby the pump may be tilted without afiectingthe indicating mechanism, and a circulatingvalve located in said baseand arranged to control the communication between said pipes and saidreservoir and tube, whereby the liquid may be circulated between thepump and the reservoir and whereby the reservoir and the tube may beindependently connected with said pipes, substantially as described.

12. A speed-indicator, comprising a liquidreservoir, an indicator-tubeconcentrically disposed with respect to said reservoir,a pump separatedfrom said reservoir and tube, and pipes connecting said reservoir andtube with the pump, whereby the pump may be tilted without affecting theindicating mechanism, substantially as described.

13. A speed-indicator comprising a liquidreservoir, an indicator-tube,and a pump interposed between said reservoir and tube and having aradiallydisposed discharge-outlet in its periphery and connected withthe indicator-tube, substantially as described.

14. A speed-indicator, comprising a liquidreservoir, an indicator-tube,and a pump having a radially and centrally disposed outlet in theperiphery of its wall, the reservoir being connected with the suctionand the indicator-tube with the discharge of the pump,

substantially as described.

15. A speed-indicator comprising a liquidreservoir, an indicator-tubeconcentrically disposed with respect to said reservoir, a pump separatedfrom said reservoir and tube, a pipe connecting said reservoir with thesuction of the pump and a pipe connecting said indicator-tube with thedischarge of the pump, whereby the pump may be tilted without affectingthe indicating mechanism, substantially as described.

16. A speed-indicator comprising a liquidreservoir, an indicator-tube, apump separated from said reservoir and tube and having aradially-disposed discharge pipe opening from its periphery, thereservoir being connected with the suction and the indicatingtube withthe discharge of the pump, whereby the pump may be run in eitherdirection and may be tilted without affecting the indicating mechanism,substantially as described.

17. A speed-indicator, comprising a liquidreservoir, an indicator tube,a pump interposed between the reservoir and indicatortube, and avalve-plug interposed in the connections between the reservoir,indicatortube and pump whereby communication may be established or cutoff between the reservoir, indicator-tube and pump and wherebyresistance may be interposed between the pump and indicator-tube tocheck the vibration of the liquid, substantially as described.

18. A speed-indicator, comprising a liquidreservoir, an indicator-tube,a pump interposed between the reservoir and indicatortube, and avalve-plug interposed in the connections between the reservoir,indicatortube and pump and having a channel to connect the discharge ofthe pump and the indicator-tube, a second channel to connect thedischarge of the pump and the reservoir and a projection to establish orcut 0E communication between the reservoir and the suction.

of the pump whereby communication may be established or cut off betweenthe reservoir, indicator-tube and pump and whereby resistance may beinterposed between the pump and indicator-tube to check the vibration ofthe liquid, substantially as described.

This specification signed and witnessed this 22d day of January, A. D.1903.

- CURTIS HUSSEY VEEDER. In presence of- E. BARBIE SMITH, W. B. DUNNING.

